Why does my json data changes while processing it?

Question

I have an json message as shown below

 static string s = @"{
'SampleNumber': '1605',
'Observations': [
    {
        'Value': 170.116262869025,
        'UpperManufacturerRange': 174.00783830400004,
        'LowerManufacturerRange': 166.00783830400004,
        'UpperControlRangeFromDevice': 174.00783830400003,
        'LowerControlRangeFromDevice': 166.00783830400003
    }
],
'LastUpdatedUtcTime': '2018-10-30T11:39:19.784942+00:00'
}";

This is my console application https://dotnetfiddle.net/nW7oqj

When I check the values in selectedJObject numeric values are changed!

174.00783830400004 changed to 174.00783830400005

float maths? Did you try to use decimal fields and try the experiment again? — peeyush singh, Mar 06 '19 at 08:22
@phuzi what is the solution? before marking for close kindly help so that beginners can learn, — kudlatiger, Mar 06 '19 at 08:37
@kudlatiger, create the class, use decimal instead of float as property type. — xdtTransform, Mar 06 '19 at 08:39
Kud here is a brunch of link: [Handling decimal values in Newtonsoft.Json](https://stackoverflow.com/questions/24051206/handling-decimal-values-in-newtonsoft-json) — xdtTransform, Mar 06 '19 at 08:41
[Json.NET decimal precision loss](https://stackoverflow.com/questions/51205166/json-net-decimal-precision-loss) — xdtTransform, Mar 06 '19 at 08:41
[Json.NET Primitive Types - use Decimal instead of Double](https://stackoverflow.com/questions/15617963/json-net-primitive-types-use-decimal-instead-of-double) — xdtTransform, Mar 06 '19 at 08:42
Basically there is a Json.Net property in the converter for that if you don't want to generate the class. — xdtTransform, Mar 06 '19 at 08:46

score 1 · Accepted Answer · answered Mar 06 '19 at 08:30

This is due to floating point math.

Try to use the following class to convert, the decimal property ensures that accuracy for numbers is maintained.

public class Test
{
    public string SampleNumber;
    public string Status;
    public int QualityControlType;
    public object[] CustomFields;
    public Test1[] Observations;
}

public class Test1
{
    public object Parameter;
    public decimal UpperManufacturerRange;
}

public static void Main()
{
         var result = Newtonsoft.Json.JsonConvert.DeserializeObject<Test>(s);            
         Console.Write(result.Observations[0].UpperManufacturerRange);
}

You will see now the numbers is same, i.e., precision is accurately maintained.

Why does my json data changes while processing it?

1 Answers1